Centrifugal impeller



Dec. 19, 19-61 N. E. T. YGGE CENTRIFUGAL IMPELLER 3 Sheets-Sheet 1 Ill 7 6 5 Z w Z 7, 2 m 7U, e D d e l .1 P.

Dec. 19, 1961 N. E. T. YGGE 3,013,501

CENTRIFUGAL IMPELLER Filed Dec. 27, 1956 3 Sheets-Sheet 2 Dec. 19, 1961 N. E. T. YGGE 3,013,501

CENTRIFUGAL IMPELLER Filed Dec. 27, 1956 3 Sheets-Sheet 3 INVENTOR jVz/s fri/f rszzen lge BY AW-9% ATTORNEY United States Patent O 3,013,501 CENTRIFUGAL IMPELLER Nils Erik Torsten Ygge, Gayle, Sweden, assignor to Aktieholaget Skoglund & Olson, Gavle, Sweden, a corporation of Sweden Filed Dec. 27, 1956, Ser. No. 630,825 3 Claims. (Cl. 103-103) This invention refers to centrifugal impellers for centrifugal pumps, turbo blowers, turbines or the like and is more particularly concerne-d with a new and improved impeller having special advantages for use in centrifugal pumps for handling thick or viscous fluids or fluids containing foreign matter in suspension, for example, sewage or stock.

Clogless impellers for centrifugal pumps designed to handle such fluids Vare well known. They are called clogless owing to the fact that the danger of the pump becoming clogged will be reduced to a minimum.

-In using conventional impellers of this type difficulties may be encountered due to radial unbalance because the outlet of the impeller is not active on more than a part of its periphery and also because the number of vanes sometimes is limited to two, thus decreasing the pumping head. In some of these centrifugal pumps `a special section with a -booster impeller or propeller is necessary to feed the liuid to the inlet of the principal impeller.

It is an object of this invention to provide a new and improved impeller completely overcoming the above mentioned drawbacks and yielding improved operation.

The invention is featured by the provision of a centrifugal pump impeller of the single suction type in which the fluid passages or channels extend from an inlet area surrounding the hub on one side of the impeller to the circumference with an even number `of vanes. forming the channels. The vanes are formed in such a way that their planes at the outlets are substantially parallel to the drive shaft and gradually turn over alternately in opposite directions so as to emerge at the inlet and to form-a ring concentric to the drive shaft which dividesthe inlet area into inner and outer concentric portions with the channels thus generated beginning alternately inside and outside the above mentioned concentric ring. A further consequence is, that inner end portions of the vanes near the concentric ring' are merged in screwformed surfaces, which when the pump is working, will `feed uid into the impeller inlet. i

Further objects, features and advantages of the invention will become apparent from 'the following `detailed description and the accompanying drawings illustrating presently preferred embodiments thereof, in which like numerals refer to like parts in the several views and `in which: i

FIG. l is a view in elevation of the inlet side of -one form of impeller according to the invention;

FIG. 2 is a side view of a portion of the impeller shown in FIG. l illustrating the manner in which the salme is mounted in the pump housing;

FIG. 3 is a vertical sectional view taken onv line 3 3 of FIG. l; l' A A FIG. 4 is a vertical sectional view taken on line 4 4 of FIG. 3;

FIG. 5 is a fragmentary vertical sectional view taken on line 5 5 of F'IG. 3;

FIG. 6 is a sectional view similar to FIG. Staken on line 6 6 of FIG. 3; l

FIG. 7 is a vertical sectional view taken all the Way through the impeller on line 7 7 of FIG. 3;

FIGS. 8 and 9 are developed arcuate sectional, views taken on lines 8 8 and'9 9, respectively, of FIG. 7;

FIG. l0 is a View perspective of a somewhat modified form of impeller in accordance With the invention omitting integral side walls, the impeller being adapted to be mounted in a housing suchas shown in FIG. ll whose walls provide the necessary side walls;

FIG. ll is a view similar to FIG. 2 but in section show ing the manner of mounting the embodiment of FIG. l0 within Ia housing; land FIG. 12 is a view similar to that of FIG. ll, illustrating a still further modified form of impeller in accordance with the invention as mounted in a pump housing.

FIG. 13 is a perspective View of the impeller of FIG.

The form of the novel impeller shown in FIGS. 1-9 is indicated generally by the numeral 16. It is a single suction impeller having an even number of vanes. It is adapted to be mounted on the usual drive shaft 18, receiving the same in the aperture 19, and to revolve within a housing indicated by broken lines in FIG. 2 and denoted by the numeral 20. In this for-m of the invention, the front and rear side walls which enclose the channels or passages formed by the vanes are integral and revolve with the impeller, `as will hereinafter be more fully described. The particular impeller shown is provided with six vanes indicated alternately by the numerals 22 and 24 and having corresponding impelling or drive surfaces 22a and 24a and trailing surfaces 2213 and 24b defining fluid passages or channels therebetween. On the inlet side of the impeller as indicated by arrows in FIGS. 2 and 3, the fluid passages formed by the vanes are closed on one side by a ringlike member 26 and on the opposite side by a wall 28. The member 26 is dished so that at the circumference of the impeller it lies in a plane transverse to the axis of the impeller while at the inlet area of the impeller it forms a cylindrical wall 26a.

The vanes 22 and 24 commencing at the circumference of the impeller (the outlet) turn in opposite directions approaching the hub of the impeller and merge into a cylindrical ring or wall 30 which surrounds the impeller hub portion 31 and is concentric with the axis thereof. This Wall divides the inlet area into inner and outer concentric inlet portions. The paths vfollowed by the Huid pumped may be readily traced from inlet to o-utlet when it is observed that the three channels delined by the surfaces 22b-24a lead from the inlet portion located radially outwardly of the ring 30 whereas the three channels defined by the surfaces 24h-22a establish communication between the inside of the ring 30 and the circumference of the impeller. Stated in another way, the active surfaces of the im# peller are defined by generatrices which, when passing from the inlet area to the circumference, start as portions of a cylinder concentric with the impeller axis and gently curve and turn over alternately in opposite directions eventually to become the separate driving and trailing surfaces lof each vane, which surfaces at the tips of the vanes lies in planes parallel to such axis.

FIGS. 4-7 are views taken progressively inwardly of i the impeller starting from the inlet area thereof. From a consideration of these sections and of the developed v sectional views of FIGS. 8 and `9, the turning in opposite directions of the vanes leading to the Special result should be readily apparent.

Starting at the outlet at the circumference of the im-` peller, the contours of two consecutive vanes 22 and 24 willbe considered.v At the circumference their lplanes are parallel both to each other yand to the axis of the impeller shaft (FIG. 8). On an arc (9 9, FIG. 7) further in from the peripheral surface, these same vanes will be seen to have commenced to turn, the vane- 22 being turned in one direction and the vane 24 in the other (FIG. 9). Further toward the inlet on line 6 6 of FIG. 3,

the vanes have turned substantially 90 so as to merge into each other (FIG. 6), and in FIG. 5 the angle between them has completely disappeared. In FIG. 4 the walls are now completely merged and are approaching a cylinder 30 which they become at the inlet area of the impeller (FIGS. 1 and 3). The edge 30a of the Wall 30 thus provides a batlie directed against the inlet stream dividing the inlet area of the impeller into two concentric parts so that part of the fiuid stream will pass through those channels which open on one side of the wall 30 and the remaining portions will pass into those channels which open on the other side of the wall 30. In this embodiment `the radial outer limit of that part of the inlet area which lies radially outwardly of the edge 30a is defined by the edge 26a of the closure 26.

FIGS. 10-12 illustrate modifications which may be made of the impeller in accordance with the invention. As seen in FIG. 10, the walls 28 and 26 have been eliminated leaving the vanes free, the remaining portions of the impeller remaining as before and being denoted by corresponding numerals. This figure shows also one of the apertures 34 through which the fluid passes from the inner intake area to the pumping blades. In this form of the invention, the impeller is adapted to be mounted Within a housing 40 (FIG. 11) whose walls have been specially shaped as at 40a and 40b to fit closely the configuration of the vanes. In this embodiment these wall portions replace the revolving wall portions 28 and 26 f the previous embodiment. The impeller discharges into the outlet chamber 42 of the housing.

In the still further modified embodiment shown in fragmentary view in FIG. 12, and in perspective in FIG. 1'3, the impellers integral rear wall 28 has been retained. However, the front wall 26 has been eliminated and the portion 40b of the housing 40 having close running fit with the vanes 22 and 24 is the equivalent of the integral wall 26 of the first described embodiment.

The operation of the novel impeller according to the invention will be evident from the foregoing detailed description. In the embodiments shown, six vanes have been provided for naturally and simply transferring energy to the fluid. The edge 30a of the concentric cylindrical ring 30 provided a minimum of resistance to streaming of the fluid and it is evident that at the inlet area the channels of the impeller face in the same general axial direction as the fluid flow. Further inward, the ridges or undulations formed by the terminal portions of the vanes comprise screw-formed surfaces 30b which act upon the entering fluid tending to force the same toward the peripheral portions of the impeller where the driving surfaces 22a and 24a of the vanes produce the desired head. There being no vanes as such in the inlet area of the impeller, the impeller is especially adapted for pumping thick or viscous fiuids or fluids containing foreign material in suspension with a minimum tendency to clog.

While I have herein disclosed and described presently preferred embodiments of the invention, it will nevertheless be understood that such disclosure is by way of illustration and not by way of limitation, and that various modifications and changes may be made in the same by those skilled in the art, the invention being not in any way limited to the specific disclosure but only by the proper scope to be afforded the appended claims.

I claim: 1. In a centrifugal pump, means defining concentric inner and outer inlet areas disposed in a common plane and a cylindrical outlet area spaced axially and radially of said inlet areas, said means including coaxially rotatable vanes merging into a common cylindrical wall which separates said inner and outer inlet areas and defining angularly spaced channels extending from said inner inlet area to circumferentially spaced portions of said outlet area, and from said outer inlet area to circumferentially spaced portions of said outlet area intermediate said firstnamed portions, said vanes near said inlet areas being formed principally as screw surfaces, and the remaining portions of said vanes being formed as fluid impelling surfaces, said uid impelling surfaces being defined by generatrices which, when passing out to said outlet area gently curve and turn over alternately in opposite directions to become mutually parallel to the rotational axis.

2. In a centrifugal pump, means defining concentric inner and outer inlet areas disposed in a common plane and a cylindrical outlet area spaced axially and radially of said inlet areas, said means including coaxially rotatable vanes merging into a common cylindrical wall which separates said inner and outer inlet areas and defining angularly spaced channels extending from said inner inlet area to circumferentially spaced portions of said outlet area, and from said outer inlet area to circumferentially spaced portions of said outlet area intermediate said firstnamed portions, and further including a stationary inner housing member and a stationary outer housing member having adjacent walls arranged to form side Walls for said channels.

3. In a centrifugal pump, means defining concentric inner and outer inlet areas disposed in a common plane and a cylindrical outlet area spaced axially and radially of said inlet areas, said means including coaxially rotatable vanes merging into a common cylindrical wall which separates said inner and outer inlet areas and defining angularly spaced channels extending from said inner inlet area to circumferentially spaced portions of said outlet area, and from said outer inlet area to circumferentially spaced portions of said outlet area intermediate said firstnamed portions, said means further including a wall forming a side wall for said channels integral with and revolving with said vanes and a housing member forming a second side Wall for said channels, the portion thereof nearest said inlet areas being shaped as a cylinder and defining the radially outer boundary of the outer inlet area.

References Cited in the file of this patent UNITED STATES PATENTS 1,503,776 Weil Aug. 5, 1924 1,889,816 White Dec. 6, 1932 2,240,653 Jenkins et al. May 6, 1941 2,547,786 Seinfeld Apr. 3, 1951 2,658,455 Seinfeld Nov. 10, 1953 2,827,261 Parker et al. Mar. 18, 1958 2,853,019 Thornton Sept. 23, 1958 FOREIGN PATENTS 27,752 Finland Nov. 30, 1955 146,760 Sweden Aug. 31, 1954 345,973 Great Britain of 1931 644,600 France June 12, 1928 719,248 Great Britain Dec. 1, 1954 

